Atopic Dermititis (Eczema)

Imagine having a very itchy (pruritus), very dry (xerosis) skin rash everyday, in those areas that tend to sweat and be moist; the creases of the neck, elbows, knees and waist.  Scratching becomes irresistible and if severe enough, leads to infection.  We’re not talking about a simple case of itching or even hives.  We’re describing someone with atopic dermatitis or eczema; an allergic skin rash that may be associated with allergies in as much as 75% of individuals.  Eczema is also very common in younger patients, affecting 2-5% of children. 

How do we diagnose eczema?  Eczema, like allergy and asthma, is a genetic disease.  A family history of atopy (allergy with positive skin tests) alone is necessary but not sufficient.  Eczema begins early, before the age of two, and it is unusual to have eczema appear after the age of five.  In very young legs, and can spread everywhere.  Older children and adults have eczema on inner creases of elbows and legs, which can also spread to the whole body.  Eczema is always pruritic and very dry, which can lead to scratching and infection. 

So how is eczema treated?  Any or all antihistamines can be used for itching, but the strongest antihistamines, hydroxyzine, at higher doses may be necessary.  Topical steroids are safe and very effective, but are best mixed with skin softeners an moisturizers to ease the itching and reduce the inflammation and control dryness and itching and reduce scratching.  For the most severe cases, a short course of oral steroids may be necessary to reduce the inflammation and control dryness and itching.  Very dry patches mean the skin is open to infection with bacteria and should be treated with oral antibiotics.  Viruses can also effect the skin, the worst being herpes simplex, which is treated with acyclovir.  Fortunately, the 25% mortality rate previously seen with herpes infection, is no longer seen.

A new class of drugs, known as calcineurin inhibitors, are available for patients two years and older.  These drugs are especially for steroid resistant cases and are excellent for use on the face, but are expensive.  Pimecrolimus (Elidel), is indicated for mild to moderate eczema, whereas Tacrolimus (Protopic) is effective in moderate to severe disease.  Some studies suggest that topical steroids and calcineurin inhibitors may work best when combined.

Finally, does food avoidance control eczema?  Studies appear controversial, but patients with eczema and allergies to foods such as eggs, milk and peanuts, should avoid these foods.  Many patients with eczema will have food environmental (dust mites, cat, dog) allergies and even asthma, and strict avoidance may help prevent acute allergy reactions.

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